The Notting Hill Carnival got off to a peaceful start after London's Metropolitan police urged those planning to attend to have fun and stay safe.

More than 5,000 police officers took to the streets on Sunday for the children's parade, which saw a total of four arrests during the event's main hours. So far 99 people have been arrested overall.

The two-day event, which is London's first major policing test since the riots earlier this month, will see 6,500 officers working in Notting Hill on Monday.

Over one million people are expected to attend the street festival. Met Police Commander Steve Rodhouse, said safety was a "top priority": "Extra stewards and police will take to the streets of West London during the bank holiday weekend."

He added: "In Notting Hill, and across London, we want people to enjoy their bank holiday safely. Come to carnival and have a great time. Our message to trouble makers is stay away, you will not be welcome."

Carnival will finish earlier than normal, at 19:00, as a result of extra safety measures police have taken.

John Tully, vice chairman of rank and file organisation for officers the Metropolitan Police Federation, warned earlier this week that the decision had the potential to cause greater tension. "There is a lot of pent up anger and frustration around certain parts of the community," he told Huff Post UK. "It might be counter productive [to shut the event early] because a lot of people turn up after the parade after the floats, they turn up for the sound-systems, if they're closed down early we could cause problems."

Mayor of London Boris Johnson warned troublemakers to stay away in a statement on Saturday: "Carnival is one of the most exciting events of the year and we want Londoners and visitors to the capital to have a safe and enjoyable time. The police have been targeting potential troublemakers and anyone thinking of causing trouble should stay away. This is a Carnival for the people – let's show the world we know how to throw a party and have a good time.

On Monday afternoon the Metropolitan Police said they had implemented Section 60 and section 60 AA of the Criminal Justice and Public Order Act 1994, which enables them to force festival-goers to remove clothing that they believe has the main purpose of concealing their identity. It also gives the officer the power to seize items.